In GPS receiver systems, a standalone GPS receiver system, and an assisted GPS receiver system are available. In the standalone GPS receiver system, a position of an object is determined by the system alone. In the assisted GPS receiver system, a position of an object is determined by the system in cooperation with a location server. The standalone GPS receiver system is used in vehicle navigation systems installed in vehicles. The assisted GPS receiver system is used in mobile phone positioning systems, in which a position of an object is determined by a mobile phone in cooperation with a location server.
When the two systems are used together, a standalone GPS antenna and an assisted GPS antenna are required for the standalone GPS system and for the assisted GPS system, respectively. As a result, the number of parts in the system increases. This increases the cost and the complicity in the assembly process of the system. Moreover, a coaxial cable is required to connect the assisted GPS antenna and an assisted GPS receiver. This adds more assembly work and cost to the system.
In recent years, many vehicles have navigation systems, using a standalone GPS receiver system, as standard accessories. Therefore, chances of adding an assisted GPS receiver system to the navigation system increase when standalone and assisted GPS receiver systems are used together. In such a case, assembly work and cost in the manufacturing process of the system increase. When adding a standalone GPS receiver system to a GPS receiver system in which an assisted GPS receiver system is used, the same problem may occur.